For realizing a capacitor in a monolithically integrated signal processing circuit, there is required a certain chip area the size of which is dependent upon the capacitance of the capacitor to be realized. The higher the desired capacitance is, the larger is the required chip area.
Monolithically integrated semiconductor circuits nowadays have reached a very high degree of integration per chip. Due to the fact that the circuits to be accommodated on one chip become ever more complex and comprehensive, everyone tries to achieve a reduction of the required chip area at all locations throughout an integrated semiconductor circuit.
In case of a conventional analog-signal to square-wave-signal reshaping circuit with offset compensation, in which a parasitic capacitance of a series capacitor is not utilized in the manner according to the invention, the side of the series capacitor directed towards a signal input terminal is connected via a first changeover switch either to the signal input terminal or to a parallel capacitor. The parallel capacitor, which constitutes a first parallel capacitor, has a second parallel capacitor connected in parallel thereto, which via a second changeover switch is connected either to the signal input terminal or the first parallel capacitor.
Switches that are monolithically integrated in semiconductor circuits are formed by electronic switching components, mostly in the form of switching transistors which may be MOS transistors. While an ON/OFF switch can be composed with one such switching transistor, a changeover switch requires two such switching transistors. A changeover switch thus needs at least twice the chip area as an ON/OFF switch.